An analytical expression for the specific capacity of lithium ion cells

Abstract

The concentration of lithium ions in the cathode of lithium ion cells has been obtained by solving the materials balance equation ac 1/2 D a2c ajn(l_t+ ) at ax ~ E by Laplace transform. On the assumption that the cell is fully discharged when there are zero lithium ions at the current collector of the cathode, the discharge time ta is obtained as "c = --ln +--2E1.2 J 6 which, when substituted into the equation C = ItJM, where I is the discharge current and M is the mass of the separator and positive electrode, an analytical expression for the specific capacity of the lithium cell is given as ~MDE 1/2 L-2-~. ~ ~-~-